Method of uniting materials



Jamfi, 1942,. F. M.v SALISBURY ,8 9

' METHOD OF UNITING MATERIALS I Filed Sept. 30, 1939 1 2 Sheets-Sheet 1 ANODIZE PARTS I APPLY'PPIMER To ALL SURFACES APPLY ONE COAT 0F LAGQUER TO INNER SURFACE I RIVET PARTS TOGETHER TO-MAKE ASSEMBLY I STRIP PRIMER FROM OUTER SURFACE OF ASSEMBLYJ INSPECT REPRIME OUTER SURFACE I L FILIL VOIDS 0E RIVET IIIIMJRLES WITHGLIAZING FIUTTY I I L WATER'SAND OF EXCESS FUTTY FLUSl-I WITH su FAcEI L LY ONE'COAT 0F PRIMERILOVER OUTER RIVET HEADS I LIGHT WATER SAIID PRIME coAT WHERE NECESSARY TO SMOOTH SURFACE APPLY' LIGHT COAT OF PRIMER OVER SANDED SURFACES AND OVER OUTER AND INNER RIVET HEADS APPLY TWO COATS OF CLEAR LACQUER, ALUMINIZED WITH 325 MEsH ALUMINUM PASTE To OUTER SURFACE OF ASSEMBLY AND ONE COAT TO INNER SURFACE WAX WITH WHITE POLISHING WAX $2M, YMM

Jan. 6, 1942. F. M'. SALISBURY METHOD OF UNITINC MATERIALS Filed Sept. 30, 1939 2 sheets sheet 2 Outer Surface Primed, Two Coats ofAluminized Lacquer Applied Then Waxed.

Inner Surfaces Primed and Lacquered One Clear Coat Before Assembly and Lacquered One Aluminized Coat After Assembly.

Rivet Dimple Voids Filled with Puffy Sanded Flush with Surface.

' Rivet Heads Primed afler Sanding.

lnner Rivet Heads Primed before Application of Final Lacquer Coal.

Aluminized Primer 5 Primer" Y La Wax Puffy Primer Clear Primer Clear v Lacquer Primer Lac Lacquer Aluminized Lacquer giwe/wb w Fexw/r Mom/$003K Al uminized Lacquer Primer are coated with an aluminum lacquer.

Q Patented Jan. 6, i942 v I UNITED STATE S PATE T OFFICE-J Marnon onvm'rmc. MATERIALS M. Salisbury, Kenmore,.N. 1., assignorto" Bell Aircraft Corporation, Buffalo, N. Y a corporation of New York 1 Application September 30, 19:9, SeriaiNo. 297,409

4 Claims. (01. urn-11o) instance the rivet headand the dimple, is elimi- Generically the present invention relates to means for uniting structuralmembers and specifically hasreference to a riveting joint and a process for flush riveting structural members thatv are subjected to aero-dynamic and hydrodynamic forces. Although my invention finds particular application in the fabrication of airhated, producing a more permanent structure.

craft it is of course of greater scope and can be employed with excellent results in joining my thin sheet metal members. I

In view of the factthat aluminum alloyssuch as for instance duralumin are being used as structural materials for aircraft it has been found that riveting is by, far the best-method by which to join the members. Moreover since the development of the dimpled or recessed rivet this joint has been very extensively used in aircraft manufacture. j z i v An object of -,the present invention is to provide a method by which a muchsmoothersurface is, obtained over a dimpledrivet joint.-

Another object of the present invention is to provide a method for uniting structural members of aircraft which will afford a joint that has a good appearance, which'is easy to clean and which will minimize'drag.

Yet a further object isto provide a novel flush riveted joint that'iis which will-not detract from the exterior appearance of the material which has been,united.-

In thedrawings;

Figure 1 is a flow sheetsbowing one method of carrying outmy inventive concept.

Figure 2 is a fragmental view in-perspective showing the manner in which the upper surfaceof the rivet head is made flush with the primary structural member or skin.

Figure 3 is a fragmental view in. perspective I illustrating the character of theinner rivet head and the manner in which [it is attached tothe support member .or stringer.

Figure 4 is an enlarged sectional view illustrating the manner in whichthe primarystructural member, the stringer and the rivet appear after they have been subjected to my novel process.

In the speciflcationthe words primary'struc- I tural member and support member are used to designatebthe slrin of. the wings, tail surfaces, fusilage' or the like and the stringers. supportbeams and so forth re pectively.

With reference to 1 .wherein is illustrated my processit can be seen that I, first of the present invention easyto manufacture, positive in operation and any portions of the primary structural material which may be rough-are smoothed off and both.

the primary structural material and the support Lastl the materials are covered with 'a polishing wax or the like. 4 A-structural 'member of an airplane. for example a wing'processed according to-this invention, will present an excellent external appearance and be quite easy to clean. -'In addition .will be greatly minimizedand the wing will not be materially eifected by adverse weather conditiensnjyll li g y coating the parts before"fabrication, electrolitic action between the parts, for

removed and the joint is tions and so forth.

a more adequate anodize both the primary structural member and its support. A primer of any suitable character is then applied to all surfaces of both the members." The inner surface of both the primary structural memberand the support are coatedv with one; coat of lacquer. v

comprehension of my process attention is called to Figures 2 to 4 inclusive, wherein I have designated the primary structural member with the numeral I, the sup-- port'member 2, and the rivet 3., After the inner parts have been=coated with lacquer the rivet I is positioned in thedimple provided in the memj bers I and.2 andthese parts are riveted together. It can'be seenfrom Figure 5 that a non-metallic coating isfbetween all joined surfaces. The l1".- 'rangement will prevent electrolitic action between the joined members and thus produce s.

more satisfactory construction.

After .the two parts have been riveted together I the primer coating on the outside surface is then I forimp erfec- The outer surface such as mentioned in the'second phase of the 7 process and the voids'of'the rivet dimples (see Figure 4) are filled with a glazing putty. The

' excess" putty is then removed bywat'er sanding so that. the filled voids will be flush with the surface of the primary structural members.

One coat is an coated with was...

f ajprimer is then applied'tothe outer rivet heads and if necessary the surface I pontoons, gasolene tanks and the like.

may be smoothed by light watersanding. Next a light coat of primer is coated over the sanded surfaces and over the inside and outside rivet heads. a

The outer surface of the primary structural member is then coated with two coats of a clear lacquer which is aluminized with 325 mesh aluminum paste and one coat of this lacquer is applied to the surface of the support member 2.

Lastly the outer surface of the primary struc-.

tural member I is coated with white polishing wax or the like.

It is believed to be readily apparent from the above description that I have provided a flush rivet joint for'structural members which presents an excellent outward: appearance and which is easy to clean. In' addition the unit is well protected from any adverse weather conditions which may be encountered and should find particular application in the construction of Moreover, a joint made according "to this invention presents a very smooth external surface which will of course materially reduce drag.

While'I,'have shown and described the prebe understood that I do not confine myself to the precise details of construction herein set forth by way of illustration, as it is apparent that many changes and variations may be made therein, by' those skilled in the art, without departing from the spirit of the invention, or exceeding the scope of the appended claims i I claim:

' dimple on top of the coating so that the upper surfaces of the head of the rivet will be substantially flush with'the surface of the material; 7

coating so that the upper surface of the head of the rivet is substantially flush with the surface of the structural material, removing the primer coating from the outer surfaces, coating the outer surfaces with a primer, filling the voids of the dimple with glazing putty, coating the surfaces with aluminized lacquer, waxing the surfaces.

3. A method of uniting sheet metal surfaces comprising formingdimples in each'sheet adapted to lie over each other, app a priming coating to the surface, swaging a rivet in place with its head in the upper dimple and lying against ferred embodiment ofmy invention,- I wish it to v of the rivet and thev upper surface, so that the 1. A method of joining structural materialswhich includes the following steps, forming a dimple in the surface of each of the materials to bejoined, anodizing the materials, applying a primer coating to all surfaces of the materials,

the priming coating in the dimple andhaving the upper surface of the rivet head flush with the upper surface, and then'coating the upper head so that the upper surface of the head of the dimple is substantially flush with the surface of the material, and filling the voids of dimple with putty.

. FRANK M. SALISBURY. 

